Studies show that operating stress and natural frequency of the turbocharger impeller are two key parameters that affect the service life of the turbocharger. In this regard, NREC and ANSYS software are utilized in the present study to design impellers and calculate the impeller stress, natural frequency, and the inertia moment of the impeller for each baseline impeller and their modifications. Furthermore, modal tests are carried out to verify the simulation results. Finally, the compressor characteristic maps before and after the blade gradient angle optimization are compared. Obtained results show that compared with the cantilever length, the blade thickness has a remarkable influence on the blade gradient angle. Moreover, it is found that the correlation between the blade gradient angle and the first-order frequency multiplication ratio is linear. As the blade gradient angle increases, the maximum stress at the blade root of the compressor initially decreases and then increases. The value of the blade gradient angle varies within the range of 2.288°–3.955°. Moreover, the closer the gradient angle to 3.26°, the smaller the maximum equivalent stress of the impeller, and the higher the impeller strength. The greater the thickness of the blade, the longer the cantilever length of the impeller, and the greater the inertia moment. Optimizing the blade gradient angle can improve the efficiency of the compressor without changing the pressure ratio and flow rate. It should be indicated that error between the results from the simulation and the experiment is within the range 1.736%–1.254%. Therefore, the calculation results are reliable. It is concluded that the regular pattern of the blade gradient angle affects the compressor impeller stress and its natural frequency. The present article is expected to provide a helpful theoretical basis for designing an optimized compressor impeller.

研究表明，涡轮增压器叶轮的工作应力和固有频率是影响涡轮增压器使用寿命的两个关键参数。在这方面，本研究利用 NREC 和 ANSYS 软件来设计叶轮并计算每个基线叶轮及其修改的叶轮应力、固有频率和叶轮的惯性矩。此外，还进行了模态试验以验证仿真结果。最后，比较了叶片梯度角优化前后的压气机特性图。结果表明，与悬臂长度相比，叶片厚度对叶片倾斜角的影响显着。而且，发现叶片梯度角与一阶倍频比呈线性相关。随着叶片梯度角的增大，压气机叶根处的最大应力先减小后增大。叶片梯度角值在2.288°～3.955°范围内变化。而且，梯度角越接近3.26°，叶轮的最大等效应力越小，叶轮强度越高。叶片厚度越大，叶轮悬臂长度越长，惯性矩越大。优化叶片梯度角可以在不改变压比和流量的情况下提高压缩机的效率。应该指出，模拟结果与实验结果之间的误差在 1.736%–1.254% 范围内。因此，计算结果是可靠的。得出的结论是，叶片梯度角的规则模式会影响压气机叶轮应力及其固有频率。本文有望为设计优化的压缩机叶轮提供有用的理论基础。